Make java.sql.Blob object from java serialized object

Question

I have an ImageIcon which I get from an applet. It gets passed to a servlet. Now, I want to turn the ImageIcon into a blob object so that I can insert it into a database (as/400). How do I do that?

Answer 1

Hi there,
NORMALLY this is a 2-step process:
1.) Convert the ImageIcon into a byte-array
2.) Write the byte-array into the database/blob
For step 1 (this code is 'freehand'):
=====================================
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos.write(myImageIcon);
oos.close();
byte[] data = bos.getBytes();
For step 2:
============
This is often database specific, but normally you select a column of a record for update, get the blob-object from the resultset and start writing bytes to it.
BUTTTTTTTT Consider this alternate approach: Assuming the image that is being sent is always small in size, you may simply chose to base-64 encode it and store the resultant string in a varchar column. When you read it back, base-64 decode it. Although the encoding/decoding may appear to be an overhead, I'll bet you it's much faster than blob-level access, both for reads and writes. It's also portable (code-wise) and you can update images through a simple UPDATE statement. In fact, if your database supports it, you could even have a default value for the column (a default image)...